This invention relates generally to electric switches, and more particularly to a circuit interrupting device which utilizes a chemical operator for providing the motive force for separating the contacts during opening.
Electric utilities, in their attempt to minimize expenses so as to be able to supply electricity at the lowest possible cost, specify and use equipment which closely matches the performance characteristics required at the particular locations. As a result, utilities are reluctant to purchase equipment whose performance characteristics exceed those required if lower-performing equipment still meeting the requirements is available. For example, at certain voltage levels of, say 69 KV, a utility may use a power fuse to provide transformer protection for substation transformers because such fuses provide adequate interrupting capability. However, at 138 KV, such power fuses are no longer utilized since they lack sufficient interrupting capability. However, at such voltage levels as 138 KV, a normally obtainable power circuit breaker, although having adequate interrupting capabilities to provide the required protection, has performance characteristics which greatly exceed those required to provide adequate transformer protection. Therefore, manufacturers are constantly striving to build circuit interrupting devices which meet the needs of the electric utility industry, but which do not substantially exceed such requirements so as to be able to supply such circuit interrupters at the lowest possible cost.